Composition of matter



Patented Aug. 7, 1945- 1 UNITED STATES PATENT OFFICE,

comosrnon or MATTER William E. Tami, Akron, Ohio, asslgnor to The 'Firestone Tire &- Rubber Company, Akron,

01110, a corporation of Ohio Ne Drawing. Application September 10, 1942, Serial No. 457,878

3 Claims. (Cl. 260-32) This invention relates to compositions of synthetic rubber-like material made by interpolymerizing a mixture of a diolefin such as butadiene and/or its homologues with' certain polymerizable vinyl compounds, namely those of the general formula wherein A, A and A" are hydrogen atoms or alkylradicals, and B is a negative radical such as cyano, acyl, carbalkoxy, phenyl or alkyl-substitutedphenyl radicals.

The above synthetic rubber-like materials may in general be used in place of natural rubber in the rubber and plastics arts. They are in some vention to provide a new composition of matter comprising a member of the above class of syn thetic rubber-like materials.

Another object is to provide eflicient solvents and plasticizers for the said rubber-like materials.

A further object is to provide a new composition of matter suitable for use as a coating composition for another substance, and especially 1' or natural rubber.

The above and further objects will be manifest in the detailed description of the invention which follows. 7

It has now been found that the syntheticrubher-like materials, above identified, may be readily dissolved by an organic ester of the general formula, RCOOR'. wherein R is a hydrogen atom, an alkyl radical or an aryl radical and R is an alkyl or a substituted alkyl radical. Preferably, the radicals represented by R and R contain no more than ten carbon atoms each. .Examples of the preferred esters comprise butyl formate, ethyl butyl-ate, butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol mono-ethyl ether acetate, a hexyl acetate, such asmethyl amyl acetate, benzyl acetate. butyl ben'zoate, triethylene glycol di-2-ethyl butyrate, octyl acetate,

diethylene glycol mono-ethyl ether acetate and diethylene glycol mono-butyl ether acetate.

A member of the above class of rubber-like materials may be dissolved or dispersed in a preferred ester to produce a solution or dispersion suitable for use as an adhesive, impregnating or coating composition. A preferred ester, especially one of low volatility, may also be mixed with one of the synthetic rubbers to plasticize -the same. Such plasticlzer may be mixed with the rubberlike material in a conventional rubber mill or mixing apparatus, or the plasticizer maybe added to a solution or dispersion, either solvent or aqueous, of the material in a known manner.

The following examples, in which parts are by weight, are'illustrative of the invention:

Example 1 A synthetic rubber composition of the following formula is mixed on a conventional rubber mill:

, Parts Synthetic rubber-like material made by interpolymerizing 70 parts of butadiene and parts of styrene in alkaline aqueous emulsion 58 Carbon black 30 Stearic acid 2 Triethylene glycol di-2-ethyl butyrate 2.5 Antioxidant 1 Accelerator 1 1 zinc, oxide 4 Sulfur 1.5

The plasticity of the synthetic rubber is found to be substantially increased on addition of the 'above-named butyrate, and the composition is smooth and homogeneous at the end of the mixing operation. The resulting vulcanizable composition is suitable for use as the tread portion of a synthetic rubber tire.

The synthetic rubber-like material made by interpolymerizing 10 parts of butadiene and 30 parts of alpha methyl styrene may be substituted in the above formula with equivalentresults. Likewise, a synthetic rubber-like material made by interpolymerizing 68 parts of butadiene and 32 parts of ortho ethyl styrene may be substituted in the above formula to produce a satislining gasoline hose. is prepared by mixing the following formula:

' Parts Synthetic rubber-like material made by interpolymerizing '75 parts of butadiene and 25 parts of acrylonitrile in alkaline The following synthetic rubber composition is mixed:

7 Parts Synthetic rubber-like material made by in- 'terpolymerizing 65 parts of butadiene and 35 parts of methyl methacrylate in acid aqueous emulsion 60 Carbon'black 25 Stearic acid 0.'7 Diethylene glycol mono-butyl ether acetate- 2.5

Ester gum Antioxidant l Accel erator 0.8

Zinc oxide 4,

Sulfur 1 The above-composition, in the form of relatively thin sheets, is placed in about four parts of butyl formate and allowed to swell therein. A

smooth dispersion is produced on stirring. The dispersion may be thinned to a smooth paint by mixing it with three to live parts of butyl forasanass i.

come in contact during service. The paint is useful for protecting other rubber articles sub- .iect to light or oil.

mate, ethyl acetate or a mixture of esters. The

' synthetic rubber paint is adhesive to many surstrongly to the tire to protect it from the deIeterious effects of light and air. The paint may be applied to the tread grooves of a tire to leave a protective coating therein for resisting the action of oil or grease with which the tire may When applied to the sidewall 01 a Instead of thinning the above initial butyl formate dispersion with further-quantities of an ester or mixture oi! esters, a paint .may be produced by thinning the initial dispersion with gasoline or a similar petroleum hydrocarbon solvent. A smooth, stable paint is thereby produced, in-spite of the fact that the above synthetic rubber cannot be satisfactorily dispersed m gasoline alone. cement, which is of low flammability, is made by mixing two parts of a 20 per cent dispersion of the synthetic rubber compound of Example 2 in butyl formate with one part of gasoline and one part of carbon tetrachloride (or ethylene dichloride or trichloro-ethylene) Dilution of such initial ester cement with larger quantities of gasoline and/or. chlorinated hydrocarbon solvents produces a mixture which is satisfactory if used immediately, but which may separate into layers on standing.

A paint having similar properties is produced by substituting for the above synthetic rubber a synthetic rubber-like material made by interpolymerizing 70 parts of butadiene and 30 parts of methyl vinyl ketone in acid aqueous emulsion or a synthetic rubber-like material made by interpolymerizing parts of butadiene and 40 parts .of acrylonitrile in alkaline aqueous emulsion.

\ A cement of a synthetic rubber-like materialparting from the scope and spirit of the invention. v p i I claim:

l. A cement comprising butyl formate. and a synthetic rubber-like material made by interpolymerizing a mixture including butadiene and acrylonitrile.

2. A cement comprising butyl formate, a petroleum hydrocarbon solvent, and a synthetic CERTIFICATE OF CORRECTION.

' Patent, No. 2,581,588-

August 7, 191

WILLIAM E.- TANN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2; 'second column, line 51, claim 5, after the word "liquid" insert --'eoating; and that the said Letters 'Patent shouldbe read with this'correction' therein. that the same may conform to the record of the case in the Patent Office Signed and sealed. this 1st day of January, A. D. 19146.

(Seal) Lesl ie Frazer First Assistant Commissioneroii latents.

An example of this type oi' lining gasoline hose. is prepared by mixing the following formula:

' Parts Synthetic rubber-like material made by interpolymerizing '75 parts of butadiene and 25 parts of acrylonitrile in alkaline The following synthetic rubber composition is mixed:

7 Parts Synthetic rubber-like material made by in- 'terpolymerizing 65 parts of butadiene and 35 parts of methyl methacrylate in acid aqueous emulsion 60 Carbon'black 25 Stearic acid 0.'7 Diethylene glycol mono-butyl ether acetate- 2.5

Ester gum Antioxidant l Accel erator 0.8

Zinc oxide 4,

Sulfur 1 The above-composition, in the form of relatively thin sheets, is placed in about four parts of butyl formate and allowed to swell therein. A

smooth dispersion is produced on stirring. The dispersion may be thinned to a smooth paint by mixing it with three to live parts of butyl forasanass i.

come in contact during service. The paint is useful for protecting other rubber articles sub- .iect to light or oil.

mate, ethyl acetate or a mixture of esters. The

' synthetic rubber paint is adhesive to many surstrongly to the tire to protect it from the deIeterious effects of light and air. The paint may be applied to the tread grooves of a tire to leave a protective coating therein for resisting the action of oil or grease with which the tire may When applied to the sidewall 01 a Instead of thinning the above initial butyl formate dispersion with further-quantities of an ester or mixture oi! esters, a paint .may be produced by thinning the initial dispersion with gasoline or a similar petroleum hydrocarbon solvent. A smooth, stable paint is thereby produced, in-spite of the fact that the above synthetic rubber cannot be satisfactorily dispersed m gasoline alone. cement, which is of low flammability, is made by mixing two parts of a 20 per cent dispersion of the synthetic rubber compound of Example 2 in butyl formate with one part of gasoline and one part of carbon tetrachloride (or ethylene dichloride or trichloro-ethylene) Dilution of such initial ester cement with larger quantities of gasoline and/or. chlorinated hydrocarbon solvents produces a mixture which is satisfactory if used immediately, but which may separate into layers on standing.

A paint having similar properties is produced by substituting for the above synthetic rubber a synthetic rubber-like material made by interpolymerizing 70 parts of butadiene and 30 parts of methyl vinyl ketone in acid aqueous emulsion or a synthetic rubber-like material made by interpolymerizing parts of butadiene and 40 parts .of acrylonitrile in alkaline aqueous emulsion.

\ A cement of a synthetic rubber-like materialparting from the scope and spirit of the invention. v p i I claim:

l. A cement comprising butyl formate. and a synthetic rubber-like material made by interpolymerizing a mixture including butadiene and acrylonitrile.

2. A cement comprising butyl formate, a petroleum hydrocarbon solvent, and a synthetic CERTIFICATE OF CORRECTION.

' Patent, No. 2,581,588-

August 7, 191

WILLIAM E.- TANN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2; 'second column, line 51, claim 5, after the word "liquid" insert --'eoating; and that the said Letters 'Patent shouldbe read with this'correction' therein. that the same may conform to the record of the case in the Patent Office Signed and sealed. this 1st day of January, A. D. 19146.

(Seal) Lesl ie Frazer First Assistant Commissioneroii latents.

An example of this type oi' 

